If you want a currency with an expiration date, feel free to create one. Doing so will necessarily expose you to the fact that most people won't want something that will expire at a certain date and trade it for something of value that doesn't expire.
In my country during the year 2016, 8th November the government announced currencies with highest denomination like 1000₹ and 500₹ won't be valued anymore. People are supposed to reach the banks and exchange it to any other denomination. In the event of this people suffered much, because there is no money to spend and banks were full of crowd. More than 100 lost their live standing in queue.
Whats the reason for such an immediate decision ?
The government stated it a reason to fight illegal funding to terrorism and recove the black money.
If there is validity or expiry for every currency same as day to day life needs, then people will make use of it and exchange to new currencies at the right time. This way everything can be made to be in circulation rather than getting accumulated for years. Here black money can also be avoided.